Wake-induced shear layer excitation in a basic annular jet
Abstract
The excitation of the outer shear layer by the disturbances associated with the wake structures shedding from the central body in a basic annular jet is studied with the conditional sampling technique. The educed velocity perturbations show that at locations upstream of the rollup of the first thin initial vortices, the outer shear layer is already under a slight oscillation at the wake-shedding frequency. This instability which triggers the formation of the wake-induced structures in the outer shear layer and the geometrical structure of these structures seem to be governed largely by the large-scale lateral velocity fluctuations of the quasi-two-dimensional orderly pattern of the shedding wake structures in the inner region.
- Publication:
-
Aero- and Hydro-Acoustics
- Pub Date:
- 1986
- Bibcode:
- 1986aha..proc..491L
- Keywords:
-
- Annular Flow;
- Jet Flow;
- Shear Layers;
- Wakes;
- Wave Excitation;
- Flow Stability;
- Oscillating Flow;
- Two Dimensional Flow;
- Vortex Shedding;
- Vortex Streets;
- Fluid Mechanics and Heat Transfer